Cognitive rigidity and BDNF-mediated frontostriatal glutamate neuroadaptations during spontaneous nicotine withdrawal

Neuropsychopharmacology. 2020 Apr;45(5):866-876. doi: 10.1038/s41386-019-0574-6. Epub 2019 Nov 21.

Abstract

Cognitive flexibility is the ability to switch strategic responses adaptively in changing environments. Cognitive rigidity imposed by neural circuit adaptations during nicotine abstinence may foster maladaptive nicotine taking in addicts. We systematically examined the effects of spontaneous withdrawal in mice exposed to either nicotine (6.3 or 18 mg/kg/day) or saline for 14 days on cognitive flexibility using an operant strategy set-shifting task. Because frontostriatal circuits are critical for cognitive flexibility and brain-derived neurotrophic factor (BDNF) modulates glutamate plasticity in these circuits, we also explored the effects of nicotine withdrawal on these neurochemical substrates. Mice undergoing nicotine withdrawal required more trials to attain strategy-switching criterion. Error analysis show that animals withdrawn from both nicotine doses committed higher perseverative errors, which correlated with measures of anxiety. However, animals treated with the higher nicotine dose also displayed more strategy maintenance errors that remained independent of negative affect. BDNF mRNA expression increased in the medial prefrontal cortex (mPFC) following nicotine withdrawal. Surprisingly, BDNF protein declined in mPFC but was elevated in dorsal striatum (DS). DS BDNF protein positively correlated with perseverative and maintenance errors, suggesting mPFC-DS overflow of BDNF during withdrawal. BDNF-evoked glutamate release and synapsin phosphorylation was attenuated within DS synapses, but enhanced in the nucleus accumbens, suggesting a dichotomous role of BDNF signaling in striatal regions. Taken together, these data suggest that spontaneous nicotine withdrawal impairs distinct components of cognitive set-shifting and these deficits may be linked to BDNF-mediated alterations in glutamate signaling dynamics in discrete frontostriatal circuits.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adaptation, Physiological / drug effects
  • Animals
  • Behavior, Animal
  • Brain-Derived Neurotrophic Factor / metabolism*
  • Cognition / drug effects
  • Cognition / physiology
  • Conditioning, Operant / drug effects
  • Conditioning, Operant / physiology
  • Corpus Striatum / drug effects*
  • Corpus Striatum / metabolism
  • Discrimination, Psychological / drug effects
  • Discrimination, Psychological / physiology
  • Frontal Lobe / drug effects*
  • Frontal Lobe / metabolism
  • Glutamic Acid / metabolism*
  • Male
  • Mice, Inbred C57BL
  • Nicotine / administration & dosage*
  • Nicotinic Agonists / administration & dosage*
  • Substance Withdrawal Syndrome / metabolism*
  • Substance Withdrawal Syndrome / psychology*
  • Synaptic Transmission / drug effects

Substances

  • Bdnf protein, mouse
  • Brain-Derived Neurotrophic Factor
  • Nicotinic Agonists
  • Glutamic Acid
  • Nicotine